Whisker manufacturing, detection, response, and compound manufacturing apparatus and method

ABSTRACT

An invention for making productive uses of normally undesirable whiskers is provided. Embodiments of the invention include a variety of apparatuses and methods associated with forming and using whiskers as well as forming whisker compounds is disclosed. For example, whisker detection modules can be created which provide a whisker surveillance capability. The whisker detection modules can further be coupled with a whisker response system such as an alarm or insulating material dispersing system. Another aspect of the invention is providing a variety of environments or microenvironments with regard to a whisker forming structure to affect whisker creation such as maximizing whisker formation. Another example includes provision of a variety of embodiments for manufacturing compounds of whiskers of various metal and metal alloys, including structures and methods is provided. Whisker compounds produced using various embodiments of the invention can be used for various applications.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a divisional application and claims priorityto U.S. patent application Ser. No. 14/327,162, filed Jul. 9, 2014,which claims priority to U.S. Provisional Patent Application Ser. No.61/844,327, filed Jul. 9, 2013, entitled “WHISKER MANUFACTURING,DETECTION, RESPONSE, AND COMPOUND MANUFACTURING APPARATUS AND METHOD,”the disclosure of which is expressly incorporated by reference herein.The present application is also related to U.S. patent application Ser.No. 14/710,032, filed May 12, 2015, entitled “WHISKER MANUFACTURING,DETECTION, RESPONSE, AND COMPOUND MANUFACTURING APPARATUS AND METHOD,”the disclosure of which is expressly incorporated by reference herein.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

The invention described herein includes contributions by one or moreemployees of the Department of the Navy made in performance of officialduties and may be manufactured, used and licensed by or for the UnitedStates Government for any governmental purpose without payment of anyroyalties thereon. This invention (Navy Case 200,223) is assigned to theUnited States Government and is available for licensing for commercialpurposes. Licensing and technical inquiries may be directed to theTechnology Transfer Office, Naval Surface Warfare Center Crane, email:Cran_CTO@navy.mil.

BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates to creating productive uses, e.g., detectionsystems or compound manufacturing, associated with formation ornucleation and growth of hair-like protrusive metal structures that havebeen observed to form from a variety of metals and/or alloys. Thesehair-like or protrusive metal structures are sometimes described aswhiskers. Whiskers are normally viewed as undesirable emergentstructures associated with use of a variety of compounds in electronicdevice manufacturing such as tin. The cause of whisker formation hasbeen hypothesized but not clearly proven thus there is a substantialdegree of uncertainty associated with whisker formation. A large numberof defects are associated with whisker formation. Attempts to eliminatewhisker formation have largely failed including creation ofmanufacturing processes where lead use is avoided. Widespreadexperimentation and research have failed to provide needed results orcountermeasures to risks associated with whisker formation.

Disclosed embodiments of the invention include a variety of apparatusesand methods associated with forming and using whiskers as well asforming whisker compounds. For example, whisker detection modules can becreated which provide a whisker surveillance capability. Exemplarywhisker detection modules can further be coupled with a whisker responsesystem such as an alarm or whisker response system such as activation ofa moveable dispenser applying insulating or whisker negating reactivematerial on a whisker being formed. Another aspect of the inventionincludes providing a variety of environments or microenvironments withregard to a whisker forming structure to affect whisker creation such asmirroring an environment associated with a part under whiskersurveillance or maximizing whisker formation. Another example includesprovision of a variety of embodiments for manufacturing compounds ofwhiskers of various metal and metal alloys, including structures andmethods is provided. Whisker compounds produced using variousembodiments of the invention can be used for various applications.

For example, one aspect of the invention includes a method tomanufacture different types of compounds of whiskers generated from theelectroplated surfaces/substrates of metals and the alloys of themetals, such as Tin (Sn) and many other low melting metals such as Zinc(Zn), Silver (Ag), Gold (Au), Cadmium (Cd), Aluminum (Al), Lead (Pb),Indium (In), in diameters scales ranging from nm to mm and in lengths upto 10 mm or more. Formation and occurrence of these metal whiskersprotruding out of soldered areas of microelectronic devices are nuisanceto electronic circuits which cause short circuit failures, but theircompounds such as SnO₂, ZnO, etc, in various forms and generated fromnon-electroplated substrates have been researched and employed invarious applications such as gas sensors or anodes for lithium ionbatteries, etc. These nano (nm)/micro (μm) sized needle shaped compoundsare made by various non-electroplating techniques. These varioustechniques do not use the needle shaped whiskers generated fromelectroplating process to intentionally produce chemical compounds suchas oxides, nitrides, carbides, sulphides, hydrides, or any complexcompounds thereof such as carbonitrides, or sulphates etc. by generatingthe metal or metal alloy whisker and subsequently reacting them invarious environment such as Carbon, (C), Nitrogen (N), Sulfur (S),Oxygen (O), Hydrogen (H) or their combinations to generate whiskercompounds. Considering above the present innovation specifically focusesat intentionally creating whiskers of various metals such as Tin (Sn),Zinc (Zn), Silver (Ag), Gold (Au), Cadmium (Cd), Aluminum (Al), Lead(Pb), Indium (In) and alloys of the metals, and chemically reacting thegenerated whiskers in various gaseous or liquidous environments withvarious elements such as O, C, S, N, H or their combinations, with theobjective to form their whisker compounds such as SnO₂, ZnO etc. orgenerating any organometallic compounds of the whiskers. The above saidwhisker compounds can be used for any suitable application such as gassensors for SnO₂ or anodes for lithium ion batteries such as SnO₂, orZnO whiskers as battery components. Thus any application that uses thewhisker compounds produced by the above mentioned manufacturingprocedure involving generation of whiskers from an electroplatingprocess and subsequent/simultaneous chemical reaction of the whiskerswith an exposed environment will be encompassed by aspects of exemplaryembodiments of this innovation. The exemplary process stated above inthis innovation does not bound the whisker compound by extent of thechemical reaction of the electroplating produced whisker with theexposed environment, or size and shape of the original pure metal ormetal alloy whisker, and the whisker compound generated.

Additional features and advantages of the present invention will becomeapparent to those skilled in the art upon consideration of the followingdetailed description of the illustrative embodiment exemplifying thebest mode of carrying out the invention as presently perceived.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and many of the attendant advantages of thisinvention will become more readily appreciated as the same become betterunderstood by reference to the following detailed description when takenin conjunction with the accompanying drawings:

FIG. 1 shows a diagram of a electroplating bath as a whisker generatingsystem according to one exemplary aspect of an illustrative embodimentof the invention;

FIG. 2 shows a diagram of an exemplary whisker material formed on theexemplary cathode substrate shown in FIG. 1 according to an illustrativeembodiment of the invention;

FIG. 3 shows a diagram of an exemplary whisker material formed on thecathode substrate shown in FIG. 1 according to an illustrativeembodiment of the invention;

FIG. 4 shows an overview diagram of an exemplary whisker compound (e.g.oxide) manufacturing progression according to an illustrative embodimentof the invention as well as a detailed or enlarged view of a whiskercompound formation structure shown in the overview diagram whichillustrates formation of a whisker compound formation layer according toan illustrative embodiment of the invention;

FIG. 5 shows a diagram of a of whisker compound or structure asmanufactured according to an illustrative embodiment of the invention;

FIG. 6 shows a diagram of an exemplary use of a whisker compound for anapplication according to an illustrative embodiment of the invention;and

FIG. 7 shows an exemplary diagram showing a whisker compoundmanufacturing process flow chart in accordance with one illustrativeembodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

The embodiments of the invention described herein are not intended to beexhaustive or to limit the invention to precise forms disclosed. Rather,the embodiments selected for description have been chosen to enable oneskilled in the art to practice various embodiments of the invention.

Referring initially to FIG. 1, whiskers of various metals such as Tin(Sn), Zinc (Zn), Silver (Ag), Gold (Au), Cadmium (Cd), Aluminum (Al),Lead (Pb), Indium (In) and/or alloys of metals can be plated on asubstrate 11 by employing metals/or alloys as an anode 13 and thuselectroplating or electrochemically forming the anode material inwhisker form on a suitable cathode substrate 11. Employment of metals oralloys can be done by using a suitable electrolyte 19 and power supply17 to produce ions 15 of the anode material 13 for application on thecathode 11. Metals or alloys used to form whiskers can also be selectedor formed to have or generate mismatches of coefficient of thermalexpansion between a plating material and substrate. Plating thicknesscan also be controlled to maximize whisker growth for a particularcombination of plating chemistry, substrate material(s), grain structureand environmental conditions. Compounds, such as brighteners, which tendto increase or alter whisker formation, can be selected for inclusioninto a plating material. Specific substrates can be selected to have anincreased effect on whisker growth such as brass as a substrate for tin.A substrate can also have structures built in which influence whiskerformation such as temperature altering structures, e.g., heating orcooling structures, as well as mechanical stress induction sectionse.g., piezoelectric structures, which influence whisker formation.

Referring to FIG. 2, after electroplating the anode material/s 13 onsubstrate 11, the electroplated substrate/coating assembly can beremoved from an electrochemical structure, such as, for example, theelectrolytic bath 21. The substrate/coating assembly would then beexposed to suitable environments to allow the nucleation, growth andprotrusion of whiskers, e.g., needle like whiskers. Factors such as anincrease in boundary grain diffusion of a material which is intended topromote growth of whiskers thereon or in relation to as well as alteringor adjusting environmental temperature and humidity can enhance theoccurrence of whiskers. Accordingly, microenvironments or localizedwhisker formation substrate or formation structures can be created atspecific locations on substrate 11′ which increases or adjusts whiskerformation on the substrate. Such microenvironments may be created bymeans of application of one or more coatings on the substrate or bymeans of application or positioning of a microenvironment structure onthe substrate 11′ which is then injected or controlled with a particularenvironmental condition such as temperature, humidity, or other aspectthat can influence a microenvironment within the microenvironmentstructure (not shown). For example, a microenvironment structure can beformed with different chambers that have an open wall where thestructure section with the open wall can be placed in contact withsubstrate 11′ then a desired environment can then be created within thedifferent chambers by means of either inlet ports or actualenvironmental generators which are in communication with the chambers.Different microenvironments can be created with different gasses such ashydrogen sulfide being applied in the presence of silver. For example,an environmental generator might be a heating element or a source ofgenerating humidity such as a sonic generator which vaporizes water uponinjection into a chamber. Different conditions then can be measured andcontrolled in the different chambers or microenvironments. Otherpossibilities for forming microenvironments include probes or controlstructures which generate conditions in proximity to a specific point ofa substrate such as an air flow with desired humidity or lack thereofwhich creates laminate airflows of the substrate along with a differentprobe which injects a desired atmosphere between the airflows thatseparate micro environmental conditions. An exemplary embodiment of theinvention can also induce cyclical material stress inducers ortemperature cycling to generate whisker growth. Another probe structurecan be a heating structure (note shown) used to generate specific heatspots or heating of specific areas of anode material formed on asubstrate which then influence whisker growth. Another aspect of theinvention can include a system which has an array of whisker affectingmaterials which can be injected into a particular environment ormicroenvironment which can be selectively applied to adjust or controlwhisker formation. For example, different pressures or densities ofwhisker inducing compounds can be injected via injection ports ormoveable application systems. Mixing systems or chambers can be used aswell to combine materials before injection.

Another whisker formation structure (not shown) or micro-environmentalcontrol structure (not shown) can be one that induces physical stress,compressive stress, bending/stretching of part or all of the substrate,or maximizes residual stress into a substrate and anode material before,during, and/or after formation of anode material on a substrate. Anotherwhisker formation structure or micro environmental control structure(not shown) can include a structure to control or manipulate whiskers asthey form to control their position or movement so as to bend thewhisker structures due to forces such as electrostatic attraction. Thisstructure to control or manipulate whiskers can be used to manipulateformation of such whiskers to increase or control whisker formation. Ingeneral, whiskers, sometimes referred to as protrusions or structuresincluding hair-like structures, can be formed to include nodules,filaments, solid/striated, circumferential rings, or a structure withkinks/bends.

In this application, the anode 13 material is distributed into theelectrolyte using the apparatus shown in FIG. 1 however a specificformation or application of anode material 13 can also be provided forto produce a desired formation of whiskers in specific locations,densities, and forms. Another structure can be provided which retards oreliminates formation of whiskers in specific locations while increasingthem in others in order to obtain a specific or predetermined shape orquantity of whiskers in particular locations, dimensions, or forms.

Referring to FIG. 3, a process and structure is used to obtain a whiskerproduct on a substrate 11′. FIG. 3 also includes a detail view, shown aswhisker formation needles 33 which are formed on substrate 11/11′. TheFIG. 3 description is shown as a simplified structure, e.g., 11′, inaccordance with one aspect or embodiment having a coating of anodematerial 13. FIG. 3 shows needles of whiskers as produced using, forexample, electroplating process that may or may not be coupled with awhisker inducing activity, e.g., environmental exposure.

Another exemplary embodiment of the invention could include anapplication having a whisker detection module (WDM) (not shown) whichemulates environmental conditions for a device under whiskersurveillance (DUWS). A WDM can be formed as a hardware-in-the-loopsimulator which can create various approximations of DUWS as well as afully blow system which has part or all of a DUWS in a controlledenvironment. Multiple WDMs can be used for the same DUWS with matchingDUWS environment in order to increase detection accuracy. A predictionsystem can also be created which can alter conditions associated with anactual DUWS within a testing or reaction chamber which then can be usedto predict whisker formation in different scenarios includingapplication of different testing factors such as electrical power,mechanical stress, humidity, application of electric fields, impacts,temperature variations as well as cycling of one or more of thesetesting factors.

Remote sensors can be networked with the test system which then receivesreal time information from one or more DUWS in actual storage or fielduse. This system can be used with, for example, a sampling of vehicles,aircraft, satellites, etc which are in actual use and have telemetrysystems which send DUWS condition updates to the testing system e.g.,WDM. For example, an on-board system in a vehicle could have sensorspositioned in relevant areas such as, e.g., accelerator pedals, whichthen could be transmitted to a telemetry system. An embodiment of theinvention can also have a system which alerts maintenance personnel aswell as operators by means of a messaging system which sends statusupdates as well as warning signals which can be triggered by acombination of environmental factors as well as detection of patterns ofDUWS behavior which have been associated with whisker formation as aprecursor to a device failure. Thus, whisker detection can be positionednot only with the WDM but also with the DUWS. An embodiment of theinvention can then be used to correlate testing or monitoring resultsfrom both WDM and the DUWS and display/store such data for diagnosticsand response actions which can be either user generated or a trigger fora whisker response system.

An embodiment of the invention can also be directed towards DUWS withina containment shell that is both highly sensitive and highly reliableand does not create conditions during operation which might influencewhisker formation. It is also desirable to ensure that sensor systemsthemselves are not vulnerable to whisker formation. Such sensors wouldneed to be designed so they are not themselves subject to breakdown orfalse readings from whisker formation. Moreover, it is important toensure that sensor system operation does not create an unpredictableinfluence on a DUWS or WDM system. Another exemplary system can includean ability to measure and transfer environmental data to the systemoutside a containment structure which would not interfere with highlysensitive and reactive devices within a portable but isolatedcontainment shell, for example by introducing radio frequency (RF)interference into the system under test. An exemplary system can bedesigned to avoid creating electromagnetic (EM) interference, have anelectromagnetic presence, or generate an EM field/signature. Anexemplary system may also be designed to be immune from EM fields thatare created in the vicinity of the test system. Also, it may be designedto address deficiencies in existing systems such as a problem withpiezoelectric sensors (e.g., require periodic recalibration). Sincethese containers are sealed, a desired monitoring needed to show exactlywhat conditions have occurred within the container. For example,conditions monitored conditions could include temperature, humidity,vibration, and shock. An exemplary container would have individualmonitoring given containers can be in groups of multiple containers andcan sometimes be swapped out individually. Moreover, individualcontainer monitoring addressed a variety of factors such as how onecontainer on one side of a group might be too hot, while another is toocold, etc.

Another consideration was a requirement that highly precise devicesstored in sealed containers for lengthy time periods were required tofunction properly after being stored in the containers without periodicmaintenance for multiple years. These devices had precision systems thatwere calibrated when they were sealed in the container, but thecalibration could be thrown off due to a variety of factors such as hightemperature or sudden shock. An exemplary system could further bedesigned so that each container could be monitored continuously andstore sensor readings. Another useful aspect of an embodiment of theinvention is that data could be shown to a vendor of the device forwarranty purposes. Stored data could also be used for maintenancedecisions such as determining when systems stored within exemplarycontainers did not meet various system or reliability thresholds orstandards. Measurement of humidity and data temperature taken outside ofa container was not helpful given there was no guarantee that conditionsinside of a container matched external conditions. For example,maintenance systems which calculated a number of days where the ambienttemperature exceeded a threshold temperature that was used to inferdegradation of a system stored within a container resulted inreplacement of a system which did not actually need replacement andvice-versa.

In one embodiment a payload could be sensitive to electromagnetic and/orRF emissions. For example, a payload of a container can be sensitive toelectromagnetic and/or RF emissions and thus the sensors need to bepurely optical-based. In one embodiment, the tolerance data is providedby a manufacturer of a payload. In another inventive variant, readingsof sensors can be forwarded to maintenance organizations responsible forpayloads in the containers to assist in making decisions on replacementof payloads. In an additional inventive variant, an exemplary computerprogram runs on a computer whose temperature is being monitored by alogging device and reporting to a computer program.

One embodiment of the invention can include an equipment and assetmonitoring system whose operational objective is to continuously andautonomously monitor, record, and assess environmental conditions andequipment status; transfer the information to a remote location; and usethe information for immediate or future design, maintenance, orreliability decisions. An embodiment can include a central processor,data acquisition units, and sensors. Exemplary sensors can be opticaland/or powered. Optical sensors in accordance with one embodiment of theinvention can be small, lightweight, accurate, reliable, unpowered,noncorrosive, and intrinsically safe which can be used for monitoringwithin sealed containers containing sensitive payloads. Sections of thesensors which may be vulnerable to whisker formation can be specificallydesigned to eliminate or mitigate whisker formation e.g., by using leadrather than tin in component design. Another benefit of optical sensorsin accordance with one embodiment is that once they are calibrated, norecalibration is required.

Another embodiment can include all-optical, all-powered, or acombination (“hybrid”) of sensors. A system can be compatible with LocalAccess Networks (LANs) to support data transfer to or from remotelocations. One embodiment can monitor four environments: Temperature;Relative Humidity; Vibration; and Shock.

Monitored data can be used to more accurately define the actual fieldenvironment, to ensure design parameters are valid, and to betterestimate equipment and asset reliability. An embodiment of the inventionprovides actual, empirical data where it actually is and this systemaccumulates it for the entire time it is in service. Data collected canaid root failure analysis e.g., the part was too hot, thus the locationit was placed into became too hot and a new location or more cooling isneeded in the future.

An embodiment of the invention can include software created/adaptedusing LabView software. An exemplary graphical user interface (GUI) canbe created to give a birds-eye view of a module area; each exemplarymodule has eight canisters—an exemplary canister has a door on them. Anoperator of an exemplary system can monitor eight groups of eightdifferent square boxes; each exemplary box has a device in it. Anexemplary system can use red, yellow, green light to reference acontainer with instruments which indicate an environment ormicro-environment within a container is within parameters. For example,if all exemplary parameters inside of an exemplary container are intolerance—e.g., temp, humidity, shock, vibration then a sensor statuslight will show green. Where a system environment is out of tolerance,an exemplary system turns a status light red. An exemplary system givesgo/no go for monitored containers to give a user or operator of a systemwhich uses stored payloads an indication of reliability of storedpayloads and whether or not such a system should or should be used ordeployed. If an operator desires more information, an operator canselect the red light using a GUI/mouse or equivalent to show an entirecontainer with sensors at different spots. In this example, each spothas a digital display i.e. location, temp, humidity, shock, vibration.IF a parameter is out of limits, an exemplary system will indicate arelevant current readout associated with the red signal. An operator canuse a GUI to select any sensor location for more information. Anoperator can also produce a digital readout and a history for thatsensor—e.g., 24 hours, 48 hours etc. An operator can also obtain a graphof when a monitored system was out of tolerance.

For the users or maintenance personnel in remote locations away frommonitored payloads, an exemplary system can be configured to transmitall or a subset of monitored information and history. An exemplarysystem can include a software program which generates anout-of-tolerance file which is transmitted or saved to the people atsuch remote locations. Transmission can be done via a communicationnetwork which, for example, provides auto alerts to a depot/maintenancepersonnel which apprises them of a need to take action on anout-of-tolerance event. Remote personnel can communicate with a payloaduser or operator and advise them to take an action e.g., verify heatingor cooling systems working properly. An embodiment of the invention canreduce costs, provide information to make maintenance action decisions,increase reliability, and improve asset or payload availability.

An embodiment of the invention can also be used to address impact damagewhich might influence whisker formation or have secondary benefits. Forexample, if monitored containers were in an area that suffered anearthquake or an accident during shipping, an embodiment of theinvention would alert maintenance and user personnel of anout-of-parameter or threshold event, e.g., damage to payload orcontainers. An embodiment of the invention could also immediately alertuser or maintenance personnel to which devices were not capable offunctioning as designed. An embodiment of the invention can inform usersor maintenance staff which unit or payload must be removed formaintenance after an out of tolerance/threshold/parameter event e.g.,impact or major vibration damage, occurs. The invention permits users ormaintenance staff to determine what payloads can and cannot be used witha high reliability.

Sensors can include fiber optic sensors with a required dynamic rangee.g. accelerometer that uses fiber optics. An exemplary instrumentedcanister can be connected to exemplary optical sensing interrogatorsfor, e.g., vibration-shock and temperature-humidity via fiberopticcable. Fiberoptic cable may be preferred because it can be used overlong distances without loss of signal. Exemplary optical sensinginterrogators can communicate with an exemplary monitoring computer viaan Ethernet connection. An exemplary equipment monitor can comprise adata logger, such as a Pace XR5 Data Logger, which acquires exemplarytemperature of the exemplary monitoring computer and reports it back tothe exemplary monitoring computer. Exemplary optical sensinginterrogators operate by means of use of a swept laser which sends itssignal at programmed time intervals through a coupler. The exemplarycoupler sends an exemplary signal to, for example, both a 1×4multiplexer and a picowave controller. Exemplary 1×4 multiplexertransmits exemplary signal to exemplary detector modules. Exemplarypicowave controller can send exemplary signal(s) to an exemplary signalprocessor. The exemplary signal from exemplary detector module andexemplary picowave can be compared and exemplary results are sent by theexemplary detector module out to the exemplary sensors. Optical sensorfor, e.g., temperature and relative humidity, in a sealed container caninclude provision of an exemplary optical fiber strung throughout theexemplary sealed container or area of interest with a DUWS. Readings canbe taken at a variety of locations. These readings can be used tocalculate what exemplary temperature and relative humidity in exemplarysealed container are.

An exemplary layout of exemplary accelerometers to detect, e.g.,vibration and shock in a sealed container can include provision of anoptical fiber is laid out throughout an exemplary sealed container. Avariety of fiber optic accelerometers can be attached to a DUWS or a WDSor a containment structure, e.g., a closed structure or anotherstructure such as a vehicle, for a DUWS/WDS. For example, severalaccelerometers can be placed at one end of an exemplary container orcontainment structure and three at exemplary other locations. Sensorlines can be strung along an exemplary container, containment structure,or sealed container. For example, one Tri-Axial IEPE Accelerometer canbe attached to each end of an exemplary sensor line. A user interfacecan include a display of exemplary information available in real timefor an individual container. A display can also show how a reading,e.g., humidity condition, is outside of tolerance as shown, e.g., by acolored outline (red for example). Actual numbers of readings can beshown to give an operator an idea of how far in or out of tolerancedifferent readings are. An embodiment of the invention thus can providea wealth of systems which work under the circumstances discussed aboveand below.

An exemplary WDM can include a whisker test structure (WTS) that ismanufactured with the same or similar materials (as well as all or someof the same manufacturing processes) as the DUWS. The WTS could also bemade from portions of an actual DUWS. The WDM can include environmentalcontrols and/or micro-environment creating sections which interact withthe WTS so that the WTS has a same or similar condition and environmentas the DUWS. The WDM receives inputs from sensors associated with theWTS and responds accordingly. A sensor system can be implemented withthe WDM that is adapted to detect different aspects of a whisker whichis growing on the WTS such as a light sensor and a moveable light whichis rotated at different angles with regard to surfaces of the WTS thatdetects a different refraction response for specific regions of the WTSthan a pre-whisker growth condition on the WTS. A look-up table isprovided which is used to compare actual readings to a pre-whiskergrowth reading. Another possible whisker sensor can be application ofhigh voltage to the WTS which then generates a plasma discharge when thewhisker short circuits with a plurality of grounding structuressurrounding the WTS. Such a short circuit would then generate an alarmwhich could then be used to trigger a response with regard to the DUWS.Whisker responses can include application of an insulating compound toall or parts of the DUWS, remote application of an ultrasonicprobe/vacuum to a corresponding area of the DUWS associated with the WTS(where the structures are the same or similar), application of rangeswitching to deliver whisker-melting impulses to circuits of interest inproximity to a targeted whisker (e.g., corresponding to the portion ofthe DUWS correlated to a whisker on a WTS), a power down of sensitivecomponents or circuits that are in proximity to a whisker on the DUWS orpredicted area of interest on the DUWS related to the detected whiskeron a WTS, summoning maintenance personnel/robotic repair equipment, etc.A WDM can include multiple compartments having a same or similarcomponent in order to obtain a multiple verification system activatedwhen more than one same or similar WTS has a detected whisker. A WDMembodiment can also have separate whisker inducing control systems whichprovide sensing or monitoring of whisker condition equivalent areas of asingle or multiple DUWS items.

Referring to FIGS. 4 and 5, a generalized graphical depiction of astep-wise process is shown. FIGS. 4 and 5 show an exemplary placement ofwhisker forming needles substrate assembly (11′ and 33) into a reactionchamber 45 containing suitable environment 47 (such as carbon and/oroxygen and/or sulfur or any other suitable environment), to react withforming whisker needles 33 to create whisker needles 33 having a coatingor composition 13′/13″ which formed a new whisker compound 49 on thewhisker forming needle(s) 33. FIG. 4 also shows another multi-laminate,composite, or intermixed type of whisker structure 51 embodiment(substituted for 49 relative to substrate 11′) comprising a plurality ofwhisker forming needles 33 having multiple or mixed layers (13′/13″).The FIG. 4 multi-laminate, composite, or intermixed type of whiskerstructure 51 can be formed by application of multiple processing stepsas well as by use of more than one reactant compound or a variety ofreactant compounds. A single, mixed, or multilayered whisker compoundsformed with or using single or more than one material can be created bya series of processing steps.

FIG. 5 shows oxidation of a tin (Sn) 49A whisker to a tin oxide (SnO)49B and then tin dioxide (SnO₂) 49C. For example, processing steps inaccordance with one embodiment of the invention can include interactinga whisker product based on suitable reaction parameters, e.g., in areactive atmosphere having a reactant compound such as oxygen (O), togenerate desired whisker compounds e.g., whisker oxides SnO 49B thenoxides as SnO₂ 49C as shown in FIG. 5.

Suitable reaction parameters such as temperature, partial pressure, etccan be selected for inclusion into, e.g., reaction chamber 45, in orderto create various types of resultant whisker compounds. For example toobtain oxide SnO or SnO₂ on a layer (e.g., 49, 51) as shown in FIG. 5, astructure or operator would heat tin nanowires/substrate assembly (11and 33) in a reaction chamber (45) having air atmosphere (47) at≈200° C.for approximate 2 hours.

An automation system (not shown), such as a whisker detection moduleWDM, as well as a WDM which further monitors and controls whiskercompound creation or alternation, can also be used to remotely monitorand adjust conditions in an embodiment of the invention. A controller(not shown) can be provided, including one with software, which controlsvariants of a WDM, such as described herein, to create desires effectsincluding monitoring and controlling reaction parameters associated withuse of an exemplary WDM, WTS, and reaction chamber 45. Such a system canalso include a user interface (not shown) which provides an operatordetection, monitoring, and control capabilities over various aspects ofembodiments of the invention such as, for example, the WDM, WTS, andreaction chamber 45. A sensor system can also be provided which providesdata on environment(s), surfaces of structures, or materials within andassociated with an exemplary reaction chamber (e.g., 45) which can bedisplayed on a user interface.

A whisker detection alarm as well as a response system can also becoupled to an exemplary embodiment of the invention (not shown). Forexample, a dispensing or whisker response system can be applied to adetected whisker in or on a DUWS upon detection of a similar whisker ona WTS. A confirmation sensor system can be included or positioned withrespect to the DUWS to provide a confirmatory sensor system to verify anactual whisker was actually formed on a DUWS. This confirmatory systemmight detect an actual whisker that has been formed on a different partof the DUWS by means of a sensor system which can measure or collectsurface condition data on different parts of the DUWS. For example, anarticulated optical sensor can be moved along with a high powerelectromagnetic spectrum source which does not cause disruptions to aDUWS (e.g., light) or even an electron microscope which is operated in asafety mode of the DUWS which has been configured to prevent damage whenthe electron microscope is articulated over its surface. For example,the light source and optical sensor could be configured to rotate and bepositioned in a manner adapted to alter a perspective on an area ofinterest which addresses the substantial difficulty in detecting awhisker such as different profiles and very thin dimensions of whiskers.For example, a sensor system could apply a light source on an axis andthen compare an image capture of the DUWS in a known good condition thencompare the image capture. The system could then rotate ninety degrees,capture another image during application of the high intensity lightsource, and perform the same comparison of the second image capture witha corresponding known-good image capture of the same DUWS that was takenusing the same sensor along the same axis of view.

Referring to FIG. 6, whisker compounds created for a suitableapplication such as gas sensors. Once a whisker is grown then interactedwith a particular process, such as gas that chemically interacts with awhisker material, the resulting compound can be harvested and used in adesired application. For example, a whisker compound (e.g.,13′/13″/49B/49C/51) can be collected by means of an embodiment of thisinvention and deposited on a gas sensor substrate 67. Gas sensorelectrodes 65 are coupled to the whisker compound which electricallyinteracts (e.g., charge transport) with sensed gas in an environment.The gas sensor is then adapted to detect e.g., an O₂ or N₂ or CO or CO₂or H₂ Gas/Media/Environment by detecting a change in voltage applied tothe whisker compound by means of electrodes 65 and a voltmeter (notshown).

A variety of harvesting structures or techniques (not shown) can be usedin accordance with various embodiments of the invention. For example,once whisker compounds are created, ultrasonic systems could be used toshatter or separate the whisker compounds growing on a substrate.Ultrasonic systems can be applied at a resonance frequency of a desiredwhisker compound so that non-conforming segments which do not meetapproximate specifications do not shatter or are less likely to shatter.The shattered or broken-off whisker materials can then then be collectedvia a variety of collection structures (not shown) such as structureswhich generate airflows to direct such materials to specific collectionpoints e.g., filter/separation system (such as a centrifuge),electrostatic attraction, washes, and/or gravity collection into acollection structure and then used in a follow-on manufacturing process.

Referring to FIG. 7, an exemplary method for producing whisker compoundsis shown. The process discussed, e.g., in FIG. 4 or 5, can be used. Forexample, at Step 79, forming a structure which is adapted to nucleateand grow desired whiskers. At Step 81, remove the electroplatedsubstrate/cathode (11′) then inserting the substrate 11′ into anenvironment adapted to grow whiskers on electroplated substrate (11′)surface as shown, e.g., in FIG. 2 and FIG. 3. At Step 83, once thestructure with desired whiskers, e.g., modified 11′, has nucleated andgrown whiskers, then remove the substrate 11′ with whiskers and exposethe whiskers to a material or substance to chemically react with thewhiskers, e.g., expose to gas to selectively oxidize the whiskers. Inparticular, at Step 83, expose the substrate having whiskers (11′/33)formed at Step 81 to environments such as Carbon, (C), and/or Nitrogen(N), Sulfur (S), and/or Oxygen (O), and/or Hydrogen (H) or theircombinations (47) by carrying out whisker compound generating reactionprocess in a reaction chamber (45) to generate whisker compounds (e.g.,13′/13″/49B/49C/51) e.g., in FIG. 5 or FIG. 6. For example, an exemplaryprocess to chemically change structures of interest (e.g., whiskers) canbe done with an aim of altering electrical, mechanical, or structuralcharacteristics of the whiskers in areas of interest on the substrate11′. At Step 85, use the above referenced whisker compounds (e.g., e.g.,13′/13″/49B/49C/51) for various applications, e.g., a sensing medium ofa gas sensor (for various gases shown as (63) shown by an example inFIG. 6.

In one case, whiskers can be formed, the structure with theelectro-formed structures is removed from an electrolyte bath, theelectro-formed structures exposed to a material which reacts with theelectro-formed structures, e.g., oxidized, and then the structure isplaced into a target application such as a battery (e.g., as an anode).In this example, the whiskers alter texture as well as electricalperformance of the battery anode in a desirable way such as increasingsurface transfer area, improving charge attributes, as well as improvingconductivity with the battery to increase battery efficiency.

Although the invention has been described in detail with reference tocertain preferred embodiments, variations and modifications exist withinthe spirit and scope of the invention as described and defined in thefollowing claims.

What is claimed is:
 1. An apparatus for detecting and responding towhiskers comprising: at least one detection compartment; a firststructure disposed within said at least one detection compartment formedto have at least some physical, chemical, or structural characteristicscorresponding to a device under surveillance having tendencies to formwhiskers; an interaction generating unit formed to influence or generatewhisker related interactions with said first structure in said at leastone detection compartment, wherein said whisker related interactionsinclude temperature, humidity, and stress conditions associated withsaid first structure; a control unit adapted to control said interactiongenerating unit so as to approximate or match whisker generation relatedconditions associated with said device under surveillance, wherein saidcontrol unit receives whisker related condition data from said deviceunder surveillance and alters whisker generation related conditions orinteractions generated by said interaction generating unit which areapplied to said first structure; a sensor system adapted to detectwhiskers formed on said first structure comprising at least one moveableoptical sensor; a response system adapted to generate a detection signalbased on detection of at least one of said whiskers formed on said firststructure, wherein said detection signal indicates presence and at leastone approximate location of said detected at least one whisker; a userinterface adapted to display a whisker detection indicator to anoperator associated with detection signal.
 2. An apparatus as in claim1, wherein said sensor system further comprises a plurality of whiskergeneration related condition sensors.
 3. An apparatus as in claim 2,wherein said control unit is adapted to receive data from said sensorsystem and further alter said whisker generation related conditions orinteractions by altering operation of said interaction generating unit.4. An apparatus as in claim 2, wherein said sensor system is furtheradapted to capture an image and form data of said at least one whiskerformed on said first structure, said user interface is further adaptedto display said image and said form data.